Method of making casings of pneumatic tires for vehicles.



' tnvrrnn srnrns PATENT canton ERNEST HOPKINSON, OF NEW YORK, N. Y.

METHOD OF MAKER? CASINGS 01E PNEUMATIC TIRES FOR VEHICLES.

No Drawing.

To all whom it may concern:

Be it known that I, ERNEST HOPKINSON, a citizen of the United States, residing in New York city, county and State of New York, have invented a certain new and useful Method of Making Casings of Pneumatic Tires for Vehicles, ofwhich the following is a full, clear, and exact description.

This invention relates more particularly to a method of making tire casings in which is employed a fluid under pressure applied directlyyto the interior wall of the casing for supporting it during the vulcanizing treatment or for stretching or tensioning the threads or cords composing the plies of the casing to bring them to tire formation prior to vulcanization.

It has been previously suggested to subject the interior of a tire casing, either previous to or during vulcanization, to the action of I a fluid directly applied to the casing for the purpose of giving the tire either partial or complete tire formationor to maintain the formation during vulcanization. I have found however that in all such attempts -where the fabric plies composing the carcass are resisting the forming and stretching action of the fluid pressure to such an extent as would cause the casing to return to or partially to its original form if the pressure were removed, that the fluid acts detrimentally upon the unvulcanized rubber and fiber composing the plie with the result that the rubber is displaced and the fluid permitted to enter between the plies of fab ric, thereby causing separation of the plies, blowing of the rubber, blisters, etc., in the final product and completely failing to accomplish the object desired. I attribute this, in part at least, to the fact that the rubber component of the casing before vulcanization does not ofler the same resistance to the pressure of the fluid as does the fabric. Accordingly, the rubber is forced forward by the pressure-of the fluid in advance of the fabric, that is to say, the rubber is forced through the interstices of the fabric and the fluid is thus permitted to enter the interstic'es and forces itself between the plies and into the rubber with the disastrous resultsabove mentioned.

lfn building the plies composing the carcass, the threads, cords, or woven fabric composing the lies are generally treated with the rubber in a manner to fill the interstices between the fibrous elements and 'to.

Specification of Letters Patent.

Patented Dec. at. rate.

coat the plies on both sides with a continuous sheet of the unvulcanized rubber compound so that the fibrous elements are completely sheathed. It is diflicult to determine whether the fluid pressure above referred to, acting upon the unvulcanized interior wall of the cur. Whether it be one or the other or both will depend to ome extent at least upon the nature of the rubber compound and the man ner of producing the bond between the rubher and fibrous elements. In any event the rupture often begins at the innermost ply and I have found that if the interior surface can be rendered impermeable to the fluid when under the required pressure that the casing may be stretched and shaped at will and held in its stretched or reformed condition during vulcanization without encoun tering the injurious results above mentioned.

In my co-pending application, Serial No. 212,517, I have disclosed a method whereby the casing, after it has been stretched and brought to final or approximately final tire shape, may be set in this shape to a sufficient degree to prevent the undesirable returning to original form, and thereby attain a condition which will permit of the desired direct application of the fluid pressure to the interior of the casing during the final cure without the ill eflects that have heretofore followed such a treatment. My present invention is directed toward attaining the same ends and I believe I am the first to successfully vulcanize a tire casing in direct contact internally with a fluid under pressure. The present invention is however further directed to bringing the casing up to tire shape by the direct application of a fluid under pressure to the interior wall of the casing, a result which previous to this invention has never been successfully attained as far as I am aware.

My invention viewed from its broadest aspect resides in rendering a layer or stratum of the casing impervious to the fluid when subjected to the desired pressure by increasing its tenacity, and in the preferred form the interior surface of the casing is so treated that it forms a barrier to the fluid pre venting it from entering the'body of the easing not only during the vulcanizing treatrnent but :418; iiiiringgtli swam-gm @55 .sloninglofthe ea sin g tc' brings; to .tlre:

satisfactorily attained if theinterior surface;

'ca'm'zati'on, cqnditignit will Qfier;

the required resistance to 61m -a'; barrier tof the flilidupressnre while at=jthe-sametimeU permitting the 'clasing; t0 be s tretchedf and- ;.fcrmed to' the required-extent and finally; -T vulcanized; Mcreover 1 I; have i-found that during final yulcanization this partiallyv 'ilunitary vulcanized, structure and- Fin such structure Will siis'tain itsj full share 101 the 'etal which thefcarcess jected."

the interim ofa-to g'iye-it tne. shape in severalwidely V diflferentways; 'fer in} stance, 'a tire has been built upon a cdreforformand 'thenattempts made'te blow it or" 1 mold-wills by-jriea nsweffllfidprcssure intro-j du 1 1ire t1y. htweenithe forn; and inner wallof the casing, form being perfg'mt'ed f ior'thijs V purpcse nether- 'instancesithe' ffla'tabIetube-br airbaginsertedinits plgcef' 7 V r t the'casingwith thejpertially' t,he.- 1ls,o theconfiningimold. In still; n h i s nces; e "ca ii g fh s be i qfbrnied' in the shape 0f; a flat Pulley baml and then brouht'to tire "shape by subject-Q expand it from the-form against confining c'ore has entirelyw remoretl and 11 in end inflatedto expand. the'easing g flated tube or air bag simulteneeusly with the movingftbgether of the margins of the' band togfcrl'n the headsfcf the cssiiu as set; 'fo'i'th'inmy above mentioned cO-Peh V g ape? eplicaticnm lnlall instences hqweveg-the car- -b fdrmedseperate item the others, or they m y be forined' together of a cbntinilous sp w d e d g i i g lldinally. around the tire, :or Where madebf-cords,

h'nds crftapes; material may be-Wmind inethoti;

-posedithereli pon; y mey-receweiits pertedi en the '01! 'cei e cr Iother form 1 p m w m-the Ot e Pl e Will-fire t e -s e 6 partiglcure while line' at state cr after it rhss been formed- &5}. cont muoigs bsnchf It may jalsojecei ei.itspertial'cure while sup-f stretched an beingtakefitd prevent the vulcanizing nized jzfter the entire casing has been fOrmed-Qr ntiany stage of its formation. In

,ill lledillm @fiecting gthejmeterial that will "fqrmflthe subsequent plies. f 1 j 1. ;My inventicnnot hmited however-t0 .settingi pcpizrtially' villcanizing'the inner particular-manner for it may be canized stream will be finally'vulcanizedff. ca withvtheremainder Of-Lthe. tireito fQ 'm' a; y

- such 'instances, the vulcani'zin' treatment lS' lpreferebly effected by a"1ne%1 directly td th'e interior i of the casing. Fo'r w. inststnce', the support for the casingmay befmade; of metaland heated 'injany desired 7 manner to give the required partial vulcani- 'um' applied .zation to the immetliately contact:

, The'fiber alnil mhber of'the inhere15 my be associated-in any desired' manneghut I preferto 'prcvide-theusualskin coat on' instancesbeslightly t 'jckerjthan that Ordiof later applied: j

:the interiiirof the pl which may in some nerily used in order to insure a; safe margin resistance ti) the. flu d, pies nre when canized 'rinterior surface hasiheen vcbinpletedf =t6 the "stage, "which l ney jinclude' 11 the assemblztgeiof-al1}the*parts necessary to ni ese' a fi f y pa r s" them; be" sub ected to f the 5 direct action of I the interior-1y applied fluid. pressure for any} 'huflt tc fiatihhd formatibn, maybe r f0r'1ned to tii e'slflapeand then. ;.fi ns zl1y vulcamzed. while in tire shape hythe .directapjilicaticn; ofii flnidi tothe interior pressure may beexerted directly between:

the cc re dr-fonn and the inner. walls of the and the tire .bifp g'ht} thus to finals V r shape; .or the tren'sverselytcafid fro frcm-beafi bead. i endfthe 'fluiii introducediin; itsj place t6; "ffii f e m ne f Pr s n y i i h sI PIY =P u ani at n a fi h s is p is e yi ar put heiore itisbuilt into the; carcass, tliat:is 1 tcrsay,zhe foref]the' dtherf lies'are S PQIiHI stretchthe-tire t6 final shap end maintain it thus during the yulcani'zing-treatment; e Whenvusg'th word c' i in theclfiims' it Will-he understood that tlusQWord means core may-be removed entirely 'eithefthe complete 'casfng with thc' tread-j 1 1. A- methd whichcohprises 'm-find n a tire casing inithe 21139110 of fluidpressure sembl'ei, r ripen-en auxilia y inl'd ircfi centaet the" inner surface,

having the major portion of its rubber component unvulcanized and a stratum of said rubber component of increased tenacity rendering it impervious to fluid under a. predetermined pressure, to giving the casing tire shape by subject ing the lnterlor to the direct action of a fluid pressure, and finally vulcanizing the I casing.

*2. A method which comprises producing a tire casing in the absence of fluid pressure in direct contact with thev inner surface,

having the major portionfof its rubber component unvulcanized and a stratum of said rubber component forming the interior surf-ace of increased tenacity rendering it impervious to fluid under a predetermined pressure, subsequently thereto giving the easing tire shape by subjecting the said surface to the-direct action of a fluid pressure, and

finally vulcanizing' the casing. 4 x

3. A method which comprises producinga tire casing in the absence of fluid pressure In direct contact with the inner surface,

having the major portion of its rubber comonent unvulcanized and a partially vulcanized stratum, subsequently thereto subjectsubsequently thereto subjecting the said casing to the direct action of fluid pressure, and

her component of finally vulcanizing the casing.-

5. A method which comprises producing a tire casing-in the absence of fluid pressure in direct contact with the inner surface, of 'plies of fibrous material and rubberhaving the major portion of its rubber component unvulcanized and one of the plies partially vulcanized, subsequently thereto subjecting the interior of the casin to the direct action of a fluid pressure, finally .vulcanizing the'casing. V

6. The method of making a pneumatic tire casing which comprises partially vulcanizing a ply made rial, incorporating said ply and unvulcanized plies 1n the casing, subjecting the said casi'ngto the direct action of a fluid pressure applied to the interior surface thereof,

and finally vulcanizing the casing. 1

7. A method which comprises producing a tire casing in the absence of fluid pressure in direct contact with the inner surface, having the majorportion of its rubber-compo- 'nent unvulcanized and a stratum of said rubincreased tenacity rendering it impervious to fluid under a predeter- "c5 {mined pressure, subsequentlythereto giving subsequently theredering it impervious stratum of f rubber andfibrous mate-- the casing tire shape by subjecting the interior to the direct action of a fluid pressure, and finally vulcanizing the casing while maintaining a fluid pressure in direct contact'with the interior surface thereof.

S. A method which comprises producing atire casing in the absence of fluid pressure in direct contact with the inner surface, having the major portion of, its rubber compo nent unvulcanized and a partially vulcanized stratum,subsequently thereto giving the casing tire shape by subjecting the interior to the direct action of a fluid pressure, and I finally vulcanizing the casing. V

-9. A method which comprises producing a tire casing in the absence of fluid pressure in direct contact with the. inner surface, having the major portion of its rubber component unvulcanized and a partially vulcanized stratum, subsequently thereto giving the casing tire shape by subjecting the interior to the direct action of, a fluid pressure, and finally vulcanizing the casing While maintaining a fluid pressure in direct contact with the interior surface thereof;

10. A method which comprises producing a tire casing in the absence of fluid pressure in direct contact with the inner surface, having the major portion of its rubber component unvulcanized and a partially vulcanized stratum, subsequently thereto subjecting the interior of the casing to the direct action of fluid pressure, and while under a fluid pressure finally vulcanizing the casing.

11. A method which comprises producing a tire casing in the absence of fluid pressure in direct'contact with the inner surface, having the major portion of its rubber component unvulcanized and a stratum of said rubber component of increased tenacity rento fluid under' a predetermined pressure, supporting the casing thus produced upon a rigid support, subsequently thereto subjecting the interior of the casing to the direct application of fluid pres.- sureYto-bring' said casing to tire shape, and

while under afluid pressure finallylvulcanizing the casing.

12. The method of making afpneumatic tire casing the rubber and fibrous plies of which comprises rendering a which the carcass is comprised inherently impervious to fluid under a redetermined pressure in the absence of fluid pressure in direct-contact with the inner surface and.

assembling the rubber and fibrous plies under substantially uniform tension to form the carcass while maintaining the major portion of its rubber component unvulcanized, subsequently thereto subjecting the interior of the carcass to the direct action of a fluid pressure, and finally vulcanizing the carcass.

tan. method which comprises producing a tire casing'of plies of fibrous material and.

rubber in the absence of fluid pressure in direct contact with the inner surface, having the major portion of its rubber component unvulcanized and one of the plies partially vulcanized, subsequently thereto subjecting each of the plies composing the carcass to a substantially uniform tensioning by the direct application of fluid pressure, and finally vulcanizing the carcass.

I 14. A method which comprises producing a tire casing in the absence offluid pressure in direct contact with the inner surface, having the major portion of its rubber comjecting the interior of the carcass to the direct action of fluid pressure, and finally vulcanizing the carcass.

15. A method which comprises producing a tire casing of plies of fibrous material and rubber in' the absence of fluid pressure. in

direct contact with the inner surface, having the major portion of its rubber component unvulcanizedand the adhesion between the rubber and fiber of one of the plies increased,

subsequently thereto subjecting the interior of the carcass to the-direct action of fluid pressure, and'finally vulcanizing the carcass.

Signed at New York, New York, this th 30 day of January, 1918. Y j

- ERNEST HOPKINSON. 

